Fix childNode null Issue (#36)

* Fix issue where childNode is null

* Split matchScopeToNode's functionality into getAllScopes and extractNodesFromRoot and remove redundant function

* Add a test for null childNodes fix

* Update eslint

* 2.2.2

package.json

@@ -1,6 +1,6 @@
 {
   "name": "flast",
-  "version": "2.2.1",
+  "version": "2.2.2",
   "description": "Flatten JS AST",
   "main": "src/index.js",
   "type": "module",
@@ -31,7 +31,7 @@
     "espree": "^10.3.0"
   },
   "devDependencies": {
-    "eslint": "^9.16.0",
+    "eslint": "^9.18.0",
     "husky": "^9.1.7"
   }
 }

src/flast.js

@@ -120,7 +120,7 @@ function extractNodesFromRoot(rootNode, opts) {
 		const node = stack.shift();
 		if (node.nodeId) continue;
 		node.childNodes = node.childNodes || [];
-		const childrenLoc = {};  // Store the location of child nodes to sort them by order
+		const childrenLoc = {};  								// Store the location of child nodes to sort them by order
 		node.parentKey = node.parentKey || '';	// Make sure parentKey exists
 		// Iterate over all keys of the node to find child nodes
 		const keys = Object.keys(node);
@@ -134,6 +134,7 @@ function extractNodesFromRoot(rootNode, opts) {
 				if (Array.isArray(content)) {
 					for (let j = 0; j < content.length; j++) {
 						const childNode = content[j];
+						if (!childNode) continue;
 						childNode.parentNode = node;
 						childNode.parentKey = key;
 						childrenLoc[childNode.start] = childNode;
@@ -154,7 +155,7 @@ function extractNodesFromRoot(rootNode, opts) {
 		typeMap[node.type] = typeMap[node.type] || [];
 		typeMap[node.type].push(node);
 		if (opts.detailed) {
-			node.scope = matchScopeToNode(node, scopes);
+			node.scope = scopes[node.scopeId] || node.parentNode?.scope;
 			node.lineage = [...node.parentNode?.lineage || []];
 			if (!node.lineage.includes(node.scope.scopeId)) {
 				node.lineage.push(node.scope.scopeId);
@@ -255,7 +256,7 @@ function getAllScopes(rootNode) {
 	const stack = [globalScope];
 	while (stack.length) {
 		const scope = stack.shift();
-		if (scope.type !== 'module') {
+		if (scope.type !== 'module' && !scope.type.includes('-name')) {
 			scope.scopeId = scopeId++;
 			scope.block.scopeId = scope.scopeId;
 			allScopes[scope.scopeId] = allScopes[scope.scopeId] || scope;
@@ -279,30 +280,6 @@ function getAllScopes(rootNode) {
 	return rootNode.allScopes = allScopes;
 }
 
-/**
- * @param {ASTNode} node
- * @param {{number: ASTScope}} allScopes
- * @return {ASTScope}
- */
-function matchScopeToNode(node, allScopes) {
-	let scope = node.scope;
-	if (!scope) {
-		let scopeBlock = node;
-		while (scopeBlock && scopeBlock.scopeId === undefined) {
-			scopeBlock = scopeBlock.parentNode;
-		}
-		if (scopeBlock) {
-			scope = allScopes[scopeBlock.scopeId];
-		}
-	}
-	if (scope) {
-		if (scope.type.includes('-name') && scope?.childScopes?.length === 1) scope = scope.childScopes[0];
-		if (node === scope.block && scope.upper) scope = scope.upper;
-		if (scope.type === 'module') scope = scope.upper;
-	} else scope = allScopes[0]; // Global scope - this should never be reached
-	return scope;
-}
-
 export {
 	extractNodesFromRoot,
 	generateCode,

tests/parsing.test.js

@@ -104,4 +104,9 @@ describe('Parsing tests', () => {
 			assert.deepEqual(n.lineage, extractedLineage);
 		});
 	});
+	it(`Verify null childNodes are correctly parsed`, () => {
+		const code = `[,,,].join('-');`;
+		const ast = generateFlatAST(code);
+		assert.notEqual(ast, [1]);
+	});
 });